Year 8 Factorising Expressions (Common Factors) Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 8 algebraic expressions worksheet.
Year 8 Factorising Expressions (Common Factors) Worksheet — Level 2 — Practice Set 4 — Answers
Find the highest common factor of the terms and write it outside the brackets.
1.Factorise fully: 8m − 36n
Answer: 4(2m − 9n)
- Highest common factor: 4
- 8m − 36n = 4(2m − 9n)
- Check by expanding the brackets.
2.Factorise fully: 6x2 + 2x
Answer: 2x(3x + 1)
- Highest common factor: 2x
- 6x2 + 2x = 2x(3x + 1)
- Check by expanding the brackets.
3.Factorise fully: 40x − 64y
Answer: 8(5x − 8y)
- Highest common factor: 8
- 40x − 64y = 8(5x − 8y)
- Check by expanding the brackets.
4.Factorise fully: 3x2 + 2x
Answer: x(3x + 2)
- Highest common factor: x
- 3x2 + 2x = x(3x + 2)
- Check by expanding the brackets.
5.Factorise fully: 12x − 8y
Answer: 4(3x − 2y)
- Highest common factor: 4
- 12x − 8y = 4(3x − 2y)
- Check by expanding the brackets.
6.Factorise fully: 18x2 + 42x
Answer: 6x(3x + 7)
- Highest common factor: 6x
- 18x2 + 42x = 6x(3x + 7)
- Check by expanding the brackets.
7.Factorise fully: 16m + 72n
Answer: 8(2m + 9n)
- Highest common factor: 8
- 16m + 72n = 8(2m + 9n)
- Check by expanding the brackets.
8.Factorise fully: 9x2 − 3x
Answer: 3x(3x − 1)
- Highest common factor: 3x
- 9x2 − 3x = 3x(3x − 1)
- Check by expanding the brackets.
9.Factorise fully: 36m + 9n
Answer: 9(4m + n)
- Highest common factor: 9
- 36m + 9n = 9(4m + n)
- Check by expanding the brackets.
10.Factorise fully: 4x2 − 14x
Answer: 2x(2x − 7)
- Highest common factor: 2x
- 4x2 − 14x = 2x(2x − 7)
- Check by expanding the brackets.
11.Factorise fully: 36m − 27n
Answer: 9(4m − 3n)
- Highest common factor: 9
- 36m − 27n = 9(4m − 3n)
- Check by expanding the brackets.
12.Factorise fully: 8x2 + 6x
Answer: 2x(4x + 3)
- Highest common factor: 2x
- 8x2 + 6x = 2x(4x + 3)
- Check by expanding the brackets.
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.